1. Field of the Invention
The present invention relates to a combustion prechamber for a spark-ignition or diesel engine, which is formed by at least two components, an upper component including, for example, an injection or ignition device, and a lower component which seals the prechamber off from a main combustion chamber of a cylinder of the engine.
2. Description of the Related Art
For production reasons, combustion prechambers are generally designed in several parts. More particularly, production costs for combustion prechambers made of several parts are substantially reduced compared with prechambers that are produced in one piece from a single material, without impairing the combustion process or the service life of the combustion prechamber. This is because the thermally most severely stressed part comprises a high-value material, while the other part or parts can be produced from a cheaper material.
Prior art prechambers having more than one part are known in which the individual components which form the prechamber are welded together, forming a parting line. A combustion pre-chamber of this type is disclosed, for example, in German reference DE 1 065 215.
Various welding processes have already been used for the purpose of joining such components. Examples of known welding processes for joining such components include tungsten inert-gas welding (TIG), metal inert-gas welding (MIG), metal active-gas welding (MAG) and beam welding using a laser or electron beam.
However, these joining processes are complicated and expensive. In addition, a welded joint is not notch-free. Above all, a non-welded butt point remains on the inner wall which forms the pre-chamber, with the result that there is a risk of incipient cracks at this point.